Tire pressure monitoring systems are becoming very popular in many vehicles. Conventional tire pressure monitoring systems measure the current tire pressures and notify the driver if the pressure in a given tire falls below a recommended tire pressure (the factory-recommended tire pressure is often referred to as the placard tire pressure). Known tire pressure monitoring systems can only monitor a single pressure setting for each tire. Many heavy duty vehicles, such as full size trucks and some SUVs, are sold with E-load rated tires having dual placard tire pressures (one recommended tire pressure for relatively light loading conditions and a different recommended tire pressure for relatively heavy loading conditions). Typically, the lower tire pressure setting provides improved ride comfort under lightly loaded conditions, while the higher pressure setting provides additional support needed for heavy loads.
Normally, a driver of a vehicle having dual placard tire pressures is responsible for determining the rear axle mass and, based on that mass, adjusting the rear tire pressure in an appropriate manner. It can be difficult for most drivers to accurately measure the rear axle mass of the vehicle, therefore, the resulting tire pressure adjustment may be based on simple guesswork. Furthermore, conventional tire pressure monitoring systems do not consider the vehicle mass and, therefore, are not readily capable of supporting vehicles having dual placard tire pressures.
Accordingly, it is desirable to have a tire pressure monitoring system that is suitable for vehicles having tires with dual placard pressures. In addition, it is desirable to have a tire pressure monitoring system that leverages an onboard vehicle mass estimation system. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.